Dragline fairlead



Oct. 31, 1961 c. ClMlNO DRAGLINE FAIRLEAD 2 Sheets-Sheet 1 Filed June10, 1958 INVENTOR.

CHARLES CIMINO cue/Dem xm/M,

ATTORNEYS United States Patent C) M 3,006,608 DRAGLINE FAIRLEAD CharlesCimino, Lorain, Ohio, assignor to The Thew Shovel Company, Lorain, Ohio,a corporation of Ohio Filed June 10, 1958, Ser. No. 741,133 1 Claim.(Cl. 254190) The present invention relates generally as indicated to adragline fairlead for drag buckets, scoops or the like, as are employedwith cranes and power shovels.

Hitherto, and as well known in the art, it has been proposed to provideon the turntable bed of equipment of the character referred to, a sheavehousing carrying intergeared sheaves between which the dragline cablemoves lineally as it is wound onto and wound from a winding drum carriedor mounted in the cab portion of the superstructure. In order to guidethe cable through continually varying angles with respect to saidintergeared sheaves, it has been proposed to provide a secondary sheavehousing which is pivotally mounted on the main sheave housing about anaxis parallel to the axes of the intergeared sheaves and which carriesanother pair of sheaves between which the cable moves at differentangles. For an example of that type of dragline fairlead, see the patentto E. J. Wilson, Pat. No. 2,043,362, granted June 9, 1936.

It also has been proposed heretofore to provide a swivelly mountedsheave housing in which the sheave groove in which the dragline cable isengaged is disposed eccentrically with respect to the swivel axis of thehousing, whereby, when the forward end of the cable leading to thedragline bucket or scoop is pulling at diiferent angles, the housing iscaused to swing about its swivel axis.

With the foregoing in mind, it is one principal object of this inventionto provide a simple and efficient form of dragline fairlead which is ofthe full-revolving type and which freely and instantly responds todragline cable pull in all directions whether up or down, or to eitherside.

It is another object of this invention to provide a dragline fairleadwhich is swivelly mounted about an axis coinciding with the longitudinalaxis of the dragline cable and which has guide members engaged by thecable and effective to turn the fairlead to position the sheaves thereofin the plane of the cable as defined by the portions extending from thefairlead toward the cable winding drum and toward the dragline bucket.

-It is another object of this invention to provide a dragline fairleadwhich has cable guide members formed with cam surfaces through which thefairlead is turned to proper operating position even when the angling ofthe dragline cable is directly to the side i.e., in a plane normal themedian trans-axial plane of the sheaves.

Other objects and. advantages of the present invention will becomeapparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention,then, comprises the features hereinafter fully described andparticularly pointed out in the claim, the following description and theannexed drawings setting forth in detail a certain illustrativeembodiment of the invention, this being indicative, however, of but oneof the various Ways in which the principle of the invention may beemployed.

In said annexed drawings:

FIG. 1 is a side elevation view of a motor crane designed formanipulating a dragline bucket which is adapted to be raised and loweredwith respect to the peak or tip of the boom and which has securedthereto a dragline cable passing through a dragline fairlead on PatentedOct. 31, 1961 the turntable bed to a cable winding drum in the craincab;

FIG. 2 is a side elevation view, on enlarged scale and partly incross-section, showing the dragline fairlead which constitutes thepresent invention;

FIG. 3 is an elevation view, again partly in crosssection, as viewedtoward the right from the left-hand side of FIG. 2;

FIG. 4 is a plan view of one of the opposite cable guide members; and

FIGS. 5 to 9 are cross-section views taken along the lines 5 to 9 ofFIG. 4.

Referring now in detail to the drawings, and first to FIG. 1, there isillustrated a motor crane 1 comprising the carrier 2, and a turntable 3and crane cab 4 which is mounted for rotation about a vertical axis.Within the cab 4 are the usual control levers and the like, by whichseveral cable winding drums (not shown) are actuated. The foot of theboom 5 is pivotally mounted as shown, and secured to the tip of the boom5 is a hoist cable system 6 (controlled by a boom hoist drum) forraising and lowering the boom. Suspended from the tip of the boom 5 is adragline bucket 7 which is raised and lowered by the fall cable 8 whichis wound onto and from another drum in cab 4. The dragline cable 9 isoperatively connected to the dragline bucket 7 and passes through adragline fairlead 10 mounted on the turntable bed, the cable 9 extendinginto the cab 4 and being wound onto and from yet another drum therein.

The cab 4 will also contain suitable controls by which the boom 5 isswung about a vertical axis to position the dragline bucket 7 wheredesired for digging or scraping operations and for dumping the contentsat selected places.

The dragline bucket 7 herein is shown, by way of example only, as beingof the self-filling type with an open top and digging end. When thebucket has been filled it is raised by keeping the dragline cable 9 tautand lifting on the fall cable 8 and is dumped by slacking off on thedragline cable 9. The cable 11 holds up dragline cable 9 and the bridlechains 12 While dumping the contents of the bucket 7. As evident, thedragline fairlead 10 keeps the cable 9 out of scrapingcontact with theturntable bed 3 and carrier 2 and must be capable of accommodating notonly the continually varying angles of the front portion of the cable 9between the fairlead 10 and the bucket 7 in a vertical plane but, aswell, the side casting angles due to swinging of the bucket 7 from onevside to the other as the boom 5 is swung about the vertical axis of theturntable 3.

Referring now to the dragline fairlead 10, the same, as best shown inFIGS. 2 to 9, comprises a fairlead housing 14 which is adapted to bemounted on the turntable bed 3 in fixed position and the front endportion thereof is formed with an obliquely disposed sleeve assembly 15providing recesses at its respective ends for tapered roller bearings 16and 17.

Journalled in the bearings 16 and 17 is the rearwardly and upwardlyextending tubular shank 18 of the sheave frame 19 which has an opening20 for passage of the dragline cable 9 longitudinally therethrough andwhich has opposite side plates 21, 21 provided with two pairs of bosses23 carrying the respective pins 24 on which the respective sheaves 25are mounted on bearings 26. The connection between the opposite sideplates 21 and the tubular shank 18 is strengthened by means of thereinforcing webs 27, as best shown in FIGS. 2 and 3. Each sheave 25 isformed with a peripheral groove 28 of approximately semi-circularcross-section, the axes of the pins 24 being parallel and spaced apart adistance such that the pitch diameters of the sheaves 25 are tangent tothus form a circular passage 29 therebetween which is 3 aligned with thecenterline of the tubular shank 18 of the sheave frame 19.

To the front of the sheaves 25 and between the side plates there areopposed cable guide bars or members 30 having specially formed insidefaces 31 adapted to be engaged by the dragline cable 9 to swivel thesheave frame 19 about the axis of the tubular shank 18. These cableguide members 30 are secured to the side plates 21 as by bolts and nuts32 with spacer tubes or collars 34 therebetween to maintain them inpredetermined spaced apart relation.

The cable guide members 30 are shaped as shown to enter the bight of thesheaves 25 and screws 35 may be employed to firmly secure theserearwardly extending portions to the side plates 21.

Referring now to FIGS. 3 to 9, each cable guide member 30 is formed withan inner face 31 which tapers in two directions (forwardly andoutwardly) with respect to a center ridge or vertex 36 that is parallelto the axis of rotation of the sheave frame 19 and aligned withdiametrically opposite sides of the passage 29.

From the foregoing, it can be seen that if the dragline cable 9 extendsstraight through the sheave frame 19 and passage 29 it will be uniformlyengaged between both sheaves 25. Should the bucket end of the cable 9swing upwardly or downwardly in the median transaxial plane of thesheaves 25 it will engage around one sheave 25 or the other and will beuniformly guided thereby without wear on the cable.

Said ridge 36 and the front arcuate portion 37 of each guide member 30terminates in a rounded portion 38, as shown in FIGS. to 9. Thus, acable'extending along the line 5 in FIG. 4 or along said ridge 36, will,when angled to one side or the other, from the median plane of thesheaves 25 be caused to slide down one side or the other of the innerface 31 from the vertex or ridge 36, to thereby apply a force on thecorresponding cable guide member 30 to cause the balanced sheave frame19 to turn so that the median plane of the sheaves 25 lies in the planeof the bend of the cable 9. As is evident from FIG. 2 of the drawing,the front arcuate edge portion 37 of each guide member is arcuate withthe centers of the arcuate edge portions 37 being the tangent point ofthe sheaves and, ofcourse, the axis or center line of the tubular shankportion 18.

As represented by the lines 6, 7, 8, and 9,'in FIG. 4, and thecorresponding sections, FIGS. 6 to 9, respectively, the cable 9 whenangled with respect to the median plane of the sheaves 25, will bear onone of the cable guide members 30 at progressively increasing distancesfrom the centerline or ridge 36 to keep the median trans-axial plane ofthe sheaves 25 in the same plane as the bend of the cable 9 so that thecable will be engaged properly in the groove 28 of one of the sheaves25. The inner faces 31 of the guide members 30 thus act as cams toswivel the sheave frame 19 and serve to prevent rubbing contact of thedragline cable 9 with the side portions of the sheave grooves 28.

Preferably, the cable guide members 30 are made of material of hardnesscomparable with that of the cable 9. For a cable 9 of 600 Brinellhardness, the members 30 may be of chilled cast iron. The cable guidemembers 30 keep the cable from becoming wedged between the peripheriesof the sheaves 25 and, at the same time, provide the inner cam faces 31to freely and instantly swivel the sheave frame 19 in response todragline cable pull in any direction.

Other modes of applying the principle of the invention may be employed,change being made as regards the details described, provided thefeatures stated in the following claim, or the equivalent of such, beemployed.

I therefore particularly point out and distinctly claim as my invention:

A dragline fairlead comprising a sheave frame having a tubular shankportion and carrying a pair of sheaves for rotation about parallel axesthat are spaced apart a distance such that the pitch diameters of saidsheaves are tangent, each sheave being formed with a peripheral grooveof approximately semi-circular cross-section, said sheaves thus forminga circular passage therebetween, said circular passage being alignedwith the center line of said tubular shank portion of said sheave frame;spaced tapered bearing means supporting said tubular shank for turningabout an axis coincident with the center line of said tubular shankportion, said axis being tangent to both said sheaves; and cable guidemembers fixed to said sheave frame and having central opposed ridges anduniformly sloping sides facing one another, elongated spacing collarsbetween said guide members for firmly holding said guide members apart,said collars being at the outer extremities of said guide members onopposite sides-of said ridges and being outwardly spaced from saidtubular shank bearing portions a distance, along the axis of said centerline of said tubular shank, greater than the diameter of said sheaveswhereby said sheaves may be laterally removed from said frame withoutdisassembling said fairlead, the outer edges of said guide members beingarcuate, with the center of said arcuate edges being the tangent pointof said sheaves and said axis, said guide members along said ridges thusextending substantially outwardly as far from the tangent point of saidsheaves as the outer extremities of said guide members and providing anequal elongated moment arm for all cable positions so that when a cableextending tangentially between said sheaves is pulled at an angle to theplane of said sheaves and to the center line of said tubular shankportion, the cable is caused to slide along one of said uniformlysloping sides thus exerting a turning force on said sheave frame throughsuch elongated moment arm.

References Cited in the file of this patent UNITED STATES PATENTS

